Antenna



e. A. KUMPF Dec. 4, 1951 ANTENNA 2 SHEETS-SHEET 2 Filed. May 18, 1946Patented Dec. 4, 1951 ANTENNA George A. Kumpf, Erlton, N. J., assignorto Radio Corporation of America, a corporation of Delaware ApplicationMay 18, 1946, Serial No. 670,676

7 Claims.

This invention relates to a new and useful portable directional ultrahigh frequency antenna which is particularly useful with radarequipment.

An object of this invention is to provide a light weight portabledirectional dipole antenna using a minimum space for carrying andstoring, and a minimum of time for erecting the same.

Portable antennas known in the prior art generally consumed a largeamount of time to erect. Also, the amount of space occupied by the partswas generally objectionable.

By my improved antenna invention, the antenna structure is greatlyreduced as to space requirement, and it requires a minimum amount oftime to erect.

A feature of the invention is that a vertical steel tube which supportsthe antenna by the aid of three clamp brackets. The dipoles and supportsare folded to lay flat. The antenna frame and reflecting screen arefolded in two half-sections by means of two link-hinges, one of which islocated at the extreme upper portion of the frame and the other at thelower portion. In the operating position, the frame is secured inposition by two thin steel tubes clamped at the top and bottom of theframe by turning ordinary wing thumb screws.

This invention will be clearly understood by referring to theaccompanying drawing in which:

Fig. 1 is a plan view of the antenna of this invention shown in theoperating position;

Fig. 2 is a front elevation of Fig. 1;

Fig. 3 is a side elevation of Figs. 1 and 2;

Fig. 4 is a detailed plan view of the hinged portion of the frame;

Fig. 5 is a front view of Fig. 4;

Fig. 6 is a sectional view taken on line 66 of Fig. 2 showing thesupport post, antenna support tube, clamp and bracket;

Fig. 7 is a view partly in cross-section taken along line of Fig. 3showing the dipole connections;

Fig. 8 is a cross-section taken on line 8-8 of Fig. 2; and

Fig. 9 is a crosssection taken on line 99 of Fig. 2.

Referring now in detail to Figs. 1, 2 and 3 of the drawing, there isshown an antenna system having a screen reflector l5 composed of twohalf-sections A and I53, each half-section being hinged to be foldedalong a line midway between sections. Each half-frame is composed ofthin steel tubing having the required strength. The ends of .the steeltubing are.

mitered and gas welded together as indicated at IE to form a rectangularframe. One reflector which was constructed according to this inventionwas approximately seventy-five inches long and forty-eight inches wide.This reflector was for an antenna designed for operation at a frequencyrange of about 200 megacycles. It is to be understood that antennaframes of other dimensions and for other frequencies may be employed.Each half-frame is provided with six folding dipole radiator or receptorelements l1, each preferably constituted by two elongated conductorstotalling a half wavelength overall. Dipole elements I? are supported byelongated con ductive members I8 which are welded to plates 49A of ahinge arrangement 19. Plates [9A are hinged to further plates l 93 whichare welded to horizontal members 26 of reflector l5 so that dipoleelements I! which are supported in front of reflector [5 in theoperating position may be raised to'lie adjacent the reflector in thenonoperating position. There is provided above each of hinged dipolebrackets H], a spring clamp 2! which retains the dipole elements in theraised position. The reflecting screen surface of the antenna array iscomposed of a plurality of small metallic tubes or steel wires 20 ofvarying sizes which are arranged horizontall and equally spaced in thevertical direction approximately two and five-eighths inches apart, thetubes and wires being welded at their ends to the rectangular frame IEA,N33. The length of support members I8 is such as to space the radiatingelements from the reflecting screen surface approximately one-quarter ofthe operating wavelength and, therefore, each pair of membersconstitutes in effect an insulator insofar as the radio frequency energyis concerned. An adjustable member 22, which is preferably a steel strapor shorting bar, is arranged to be adjustable to make the electricallength from shorting bar 22 to dipole l1 exactly a quarter wavelength atthe operating frequency. In some applications, member 22 may beconstructed of insulating material. The antenna array thus far describedis coupled to transducer apparatus by means of a feeeder network ofconcentric balanced transmission line, each dipole arm being preferablyconnected by the flexible transmission line cables 23 as shown iii-Fig.7, wherein a length of coaxial cable 23 is shown passing within onesupport member l8 to a point near its outer end. At this point sheathconductor is bonded to the contiguous dipole element and the centerconductor 66 is connected to the conductor of a feed through insulator61,

which in turn is connected to the opposing dipole element I! by means ofa conductive spring member 68. In this manner the dipoles are excited inthe conventional mode. The transmission lines are so arranged that theenergy is fed to the dipoles to obtain the desired radiation pattern.The transmission line cables 23 are all formed of lengths of flexiblecoaxial line comprising a center conductor and an outer conductor, theconductors being maintained in a concentric arrangement by suitableinsulation material.

Referring now in detail to Figs. 4 and 5, the two rectangular frames ISAand I5B are preferably hinged together by an improved hinged memberwhich is composed of two metallic plugs 24, each being pinned and weldedto the inner surface of tubes [5A and I5B, respectively. The forward endof each plug 24 is provided with a flat portion and an aperture toreceive two link members 25, the links being secured to members 24 bystuds '26 provided with a shoulder portion 25' which is slightly greaterin length than the thickness of the projecting portion of members 24.The length of. the spacing between the shoulder portions is such as toprevent links 25 from binding. The ends of studs 26 are riveted over toprevent them from coming loose or becoming detached. The central portionof the hinge is provided with shouldered stud 2'! which also has ashoulder at 21' and is riveted over. Members 25 are suitably shaped toprovide a stop arrangement to limit the opening of the hinge. Apreferred arrangement of such stop is shown as. comprising linkprojection 25 and pin 28.

Referring now in detail to Fig. 6, there is shown a triangular shapedsupport casting 30 which supports the antenna on a vertical steel tube29. The support casting 3B is provided with apertures 3|, 32 and 33.Aperture 32 has a split portion 34' which is formed by two extendingears 35 and 36. The ear 35 is threaded to receive a machine screw 31,and the ear 36 is drilled for sufficient clearance so that when themachine screw 31 is tightened, a support tube or pipe 29 will be clampedthereto. The casting 30 is provided with another casting 40 which servesas a clamping portion. The purpose of this latter casting is to enablethe frame to be disassembled from the pole or pipe 29. This isaccomplished by loosening threaded wing bolts or screws 48 and 49 whichare located on both ends of casting 40. These wing bolts are arranged tobe captive by burring over their ends, which prevents the bolts frombeing detached from casting 48 and becoming lost. The center wing screwstud or bolt 43 is arranged on casting 40 with a spring 44. A hinge pinis provided on the end of stud 43 when the latter is loosened andprevents the casting 40 from being separated from the support casting 30which stays with the pole 29 when disassembled. The lower portion ofpole 29 terminates in a combined rain shield and mounting support member50. The combined rain shield and support member 5H has four pivoted wingmembers 5| which are arranged to secure four support legs 52 thereto.There are three groups of support castings 30 and 40 used to support theantenna. The upper portion of each one of the castings 30 is providedwith engaging pins M and 42 for securing the castings to each half-frameI5A, 153.

In the operation of this device, as shown by Fig. 8, the antenna arrayis assembled by loosening the wing nuts 62 on each one of the supportstraps 6i, thus permitting the retaining tube to slide thereon. As shownby Figs. 1 and 2, the antenna array with the half-portions I5A and [5Bare then opened up at the hinged portion so that the tube 66 is in acentral position with respect to each half-frame ISA, I5B and the wingnuts 62 tightened. Each dipole is then loosened from the clampedposition by releasing spring 2|, and swung down on the hinge arrangement19 to the position shown in Fig. 3 and in greater detail in Fig. 9 andlocked by spring 2|. Suitable connections to the radio aparatus are thenmade to the transmission lines 23 (which in themselves form no part ofthe invention) and the antenna is then ready for operation. In placingthe antenna structure in the non-operating position again, each antennadipole is folded upward and held by the action of spring 2| engaging asupport member [8, whereby the assembly then lies parallel with theframe, and tube 60 is moved to its closed or non-operating position. Thethumb or wing nuts 62 are then tightened and the half-frames [5A and I5Bare then secured in their closed position.

What is claimed is:

1. A portable high frequency antenna comprising a central tube, aplurality of spaced apertured support members secured to said centraltube along the length thereof, a pair of half frames on opposite sidesof said central tube and secured to said support members and pivotallymovable in the apertures of said support members, a plurality ofparallelly spaced supports secured to each of said half frames, means onsaid apertured support members to clamp said half frames, a plurality ofdipoles each pivotally supported as a unit by a hinge connected to saidparallelly spaced supports to permit folding, a plurality of supportstraps secured to each half frame, a movable metallic tube clamped bysaid support straps to top and bottom portions of said frames to retainthem in the same operating plane.

2. A unitary transportable ultra high frequency antenna array comprisinga central support member, a plurality of spaced apertured supportmembers secured to said central support member along the length thereof,a reflector screen including a pair of half frames on opposite sides ofsaid central support member and secured to said support members andpivotally movable in the apertures of said support members, a pluralityof parallelly spaced supports secured to each of said half frames, meanson' said apertured support members to clamp said half frames, aplurality of dipoles each pivotally supported as a unit by a hingeconnected to said parallelly spaced supports on the front of said screento permit folding, means adjacent said hinges to retain said dipoles ina folded non-operating position, a plurality of support straps securedto each half frame, a movable metallic tube clamped to said supportstraps at top and bottom portions of said half frames to retain them inthe same operating plane, a transmission line feeder network and aswitch box secured to the rear of said screen, a rain shield arranged atthe base of said support member, and a plurality of pivoted wing memberspivoted on said rain shield for mounting said antenna.

3. An antenna structure comprising a flat screen reflector, a pluralityof spaced dipoles each having support members attached thereto, saidsupport members being pivotally mounted on said screen to permit thedipoles and supports to lie flat against said screen or in a positionwherein said supports are at 90 degrees to the plane of said screen, thedipoles being arranged mechanically parallel to each other.

4. A foldable antenna structure comprising a flat screen reflector, aplurality of spaced dipoles each having supporting members attached atthe ends thereof, said supporting members being pivotally mounted onsaid screen at the ends of said members remote from said dipoles topermit the dipoles and supports to lie flat against said screen or in aposition wherein said members are at 90 degrees to the plane of saidscreen, the dipoles being arranged mechanically parallel to each other,a second similar construction of flat screen reflector and pivotallymounted dipoles, and a plurality of hinge members secured to adjacentedges of said fiat screens for permitting said screens to remain in asingle plane or to fold together.

5. An antenna structure comprising a flat screen reflector, a pluralityof spaced dipoles each having supporting members attached thereto, saidsupporting members being pivotally mounted at one end thereof on saidscreen to permit the dipoles and supports to lie flat against saidscreen or in a position wherein said supporting members are at 90degrees to the plane of said screen, the dipoles being arrangedmechanically parallel to each other, a second similar construction offiat screen reflector and pivotally mounted dipoles, and a plurality ofhinge members secured to adjacent edges of said flat screensforpermitting said screens to remain in a single plane or to foldtogether, and means secured to both of said screens at their adjacentedges for mounting said screen in a vertical position.

6. A portable high frequency antenna structure comprising a centralsupporting member, a refleeting screen including a pair of half framesarranged on opposite sides of said supporting member and pivotallymovable thereon, a plurality of parallel spaced supports secured to eachof said half frames, means on said supporting member to clamp said halfframes, and a plurality of dipoles each pivotally supported as a unit bya hinge connected to said parallel spaced supposition wherein saidsupports are normal to the surface of said screen.

7. A portable antenna structure including a screen reflector assemblyand an array of dipole antenna elements arranged before said reflectorassembly in the operating position, said screen reflector assemblycomprising two screen reflectors arranged to fold together with thespace therebetween less than the distance between said antenna elementsand said reflector assembly in the operating position, supportingmembers attached to each of said dipole antenna elements, saidsupporting members being pivotally mounted at the ends thereof near saidreflector assembly to permit said dipole elements and attachedsupporting members to be folded to lie flat alongside said screenreflectors to occupy a space less than that between the screenreflectors when folded in the non-operating position.

GEORGE A. KUMPF.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,612,939 Neitzel et al Jan. 4,1927 1,684,009 Brown Sept. 11, 1928 2,073,085 Wells Mar. 9, 19372,082,347 Leib et a1 June 1, 1937 2,097,707 Tichenor Nov. 2, 19372,138,134 Beverage et a1. Nov. 29, 1938 2,160,053 Barbour May 30, 19392,270,314 Kraus Jan. 20, 1942 2,280,738 Bace Apr. 21, 1942 2,282,388 ZehMay 12, 1942 2,299,218 Fener Oct. 20, 1942 2,313,513 Brown Mar. 9, 19432,397,645 Brown Apr. 2, 1946 FOREIGN PATENTS Number Country Date 495,019Great Britain Nov. 4, 1938

